These Animals Are Having Hot Sex—And That's Not A Good Thing

Turn down the heat.

Increasing global temperatures because of climate change not only destroy animals' habitats and their ability to find food, but it's also changing the way they breed. For some animals, this means altering the time and path of their migration, but for others, a warmer climate means that more females are being born than males.

It sounds confusing, but here's how it works:

Sex determination is the process that regulates whether an animal is born male or female. In humans, sex is decided based on the presence or absence of a Y chromosome. Many other animals also have a similar chromosomal regulator.

Some reptiles, like sea turtles, and alligators, have temperature-based sex determination, where the chromosomes responsible for developing sex traits are either turned on (or not) based on how warm the environment is where the eggs are laid.

For instance, sea turtle eggs are buried on the beach. Eggs that are deeper in the nest tend to be cooler, leading to male sea turtles. Eggs on top, closer to the sun-warmed sand, tend to be female. Because climate change is increasing temperatures, more turtles will be born female. In other species, different temperatures have different outcomes.

So why is this a problem?

With more females being born than males, females won't be able to be as choosy when it comes to finding a mate. Not only that, but one male will breed with more females, which reduces the amount of genetic diversity in the population. Because climate change is also altering their habitat, a less diverse gene pool will leave them at a disadvantage to adapt to those changes.

Want to learn more about temperature-based sex determination and how it will affect the ecosystem?